Special to the Director's Cut Blog By Gary Levin, USA TODAY Ann Curry said a teary goodbye to her Today show colleagues and viewers Thursday as NBC prepared to announce her replacement, Savannah Guthrie, as early as Friday. Curry, 55, is exiting amid a ratings downturn at the still top-rated morning show and a perceived lack of chemistry with co-host Matt Lauer. Her abrupt departure comes little more than a year after Curry -- the show's former news reader -- took over for Meredith Vieira. "This is not as I expected, to ever leave this couch after 15 years, but I am also grateful," she said, choking up with emotion as she announced the news at 8:50 a.m., without the congratulatory tributes that accompanied Vieira's sendoff. "For all of you who saw me as a groundbreaker, I'm sorry I couldn't carry the ball to the finish line, but man, I did try." As she had told USA TODAY in an exclusive interview Wednesday, Curry said on air she has won ...